1. Field of the Invention
This invention directs itself to biopsy devices utilized for percutaneous medical procedures. In particular, this invention directs itself to a biopsy system wherein a handle is releasably coupled to a cannula assembly, providing particular advantages for the performance of vertebroplasty procedures. More in particular, the handle of the present invention includes an opening formed in a lower side thereof wherein recesses are formed in opposing interior wall surfaces of the opening for receiving respective projections formed on the hub portion of the cannula. Still more in particular, this invention pertains to a biopsy system wherein the recesses formed in the opening of the handle have terminal portions in which lower and upper locking recesses are formed for rotatively and axially displacing the cannula assembly, either toward or away from patient, respectively.
2. Prior Art
Biopsy systems are well known in the art. The best prior art known to the Applicants include U.S. Pat. No. 4,922,602; U.S. Pat. No. 5,331,972; U.S. Pat. No. 5,385,151; U.S. Pat. No. 5,807,275; U.S. Pat. No. 5,752,923; U.S. Pat. No. 5,538,009; U.S. Pat. No. 5,476,102; U.S. Pat. No. 5,257,632; U.S. Pat. No. 4,256,119; U.S. Pat. No. 4,793,363; U.S. Pat. No. 5,127,419; U.S. Pat. No. 5,634,473; U.S. Pat. No. 5,758,655; U.S. Pat. No. 5,186,197; U.S. Pat. No. 4,513,754; U.S. Pat. No. 5,036,860; U.S. Pat. No. 3,949,747; U.S. Pat. No. 5,807,277; U.S. Pat. No. 5,526,821; U.S. Pat. No. 5,429,138; U.S. Pat. No. 4,356,828; U.S. Pat. No. 4,266,555; and, U.S. Pat. No. 4,262,676.
In some prior art systems the proximal end of the cannula is accessible through an opening formed in an upper side of the handle, subsequent to removal or displacement of a cover therefor. Such systems, however, do not provide a clear field of view for the physician. Other prior art systems, such as that disclosed by U.S. Pat. No. 3,949,747, have a removable handle for selective engagement with any one of a plurality of punches and probes. However, such handle is threadedly connected to the punches and probes, and therefore only capable of rotatively driving the punch or probe in a single direction, in the tightening direction of the handle, as rotation in the opposing direction will cause the handle to disengage from the selected tip.
In still other prior art systems, such as that disclosed by U.S. Pat. No. 4,513,754, the cannula is releasably held within the jaws of a collet. As the cannula is a tube, the jaw pressure thereon is limited, in order not to crush the tube, thereby limiting the axial and rotational forces which may be transferred from the handle to the cannula.
Such deficiencies are overcome by the structure of the invention of the subject Patent Application, by virtue of the removable handle that is capable of rotating a cannula assembly in either a clockwise or a counterclockwise direction while an axial force, either toward or away from a patient is applied. The utility of the invention of the subject Patent Application is further enhanced by the formation of a grip portion on the cannula hub and the inclusion of a luer-type coupling system with the cannula hub.